Flange bolts feature a broad surface under the head which acts like a washer. These are fasteners used in automobile and industrial manufacturing. Yellow zinc plated fasteners have good corrosion resistant qualities and are a good choice for indoor and industrial applications. Grade 5: made from medium carbon steel. Quenched and tempered for higher tensile strength and holding power. Three radial bars head marking. Tensile strength: up to 1" - 120,000 p.s.i. (min), 1-1/8" dia. And up - 105,000 p.s.i. (min).